🧠From the air we breathe to the water we drink, microplastics infiltrate every corner of our lives—but what happens when they cross into our brains?
💨Plastic is all around us: your water bottle, makeup, car, and food packaging likely have at least some plastic components, but what about your dinner? Or the ocean? Or the air we all breathe? Well, microplastics have been found in all three; the question is how badly they are affecting us and what can be done about it.
Microplastics Everywhere;
Where exactly are microplastics found? Where exactly are microplastics found? According to an analysis of 26 studies, bottled water has, on average, 94.37 particles per liter, 32.27 in beer, and 4.24 in tap water. Even the air we breathe contains 9.80 particles per cubic meter. All these particles add up, meaning the average person unknowingly consumes between 78,000 and 211,000 microplastic particles annually.
The Blood-Brain Barrier Problem
The blood-brain barrier (BBB)is a selective semi-permeable membrane between the blood vessels that supply your brain and the surrounding tissue; it regulates what can and can’t leave the blood vessel and makes its way into your brain. Generally, only small, positively charged molecules like H20 can cross this barrier, keeping your brain safe from toxic substances and pathogens.
Microplastics in Brain Tissue
🔹Aside from crossing the BBB, a recent study published in JAMA Network Open has found that microplastics can enter the brain via the nasal cavity, ending up in the olfactory bulb. “Previous studies in humans and animals have shown that air pollution reaches the brain and that particles have been found in the olfactory bulb, which is why we think the olfactory bulb is probably one of the first points for microplastics to reach the brain,” said lead study author Dr. Thais Mauad, an Associate Professor of Pathology at the University of São Paulo Medical School in Brazil.’
🔹The study reveals that microplastics can reach the olfactory bulb in the human brain, indicating the olfactory pathway as a potential entry route. After examining the olfactory bulbs of 15 deceased individuals, researchers found microplastics in over half of the cases, with polypropylene as the most common polymer. Microplastics entered the brain through nasal passages, bypassing the blood-brain barrier—a previously assumed defense.
The Effects: Researching Risk
Outside of the gut, the study highlighted how inhaled microplastics may lead to respiratory symptoms, oxidative stress, and inflammation in lung tissue, potentially contributing to chronic respiratory conditions. Microplastics ingested in either manner may disrupt hormonal balance, pose risks to reproductive health, and trigger immune responses, with evidence of immune activation in human lung cells. Animal models show that microplastics can enter the central nervous system, induce neurotoxicity, and contribute to cognitive and locomotor issues, which concurs with the olfactory bulb study.
Reducing the Risk
It might seem impossible to avoid these pervasive particles, but there are a few things you can do to reduce your exposure and that of your family. The experts recommend avoiding plastic-packaged food, using glass or metal storage, and opting for fresh foods over processed ones, which often have plastic additives.